Non-Contact Respiration Sensing

ABSTRACT

A head mounted device may include one or more interferometric sensors positioned and oriented in a housing to sense particle movement caused by respiration of a user. Interferometric signals from the one or more interferometric sensors may be used to determine respiration information about the user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a nonprovisional and claims the benefit under 35U.S.C. § 119(e) of U.S. Provisional Application No. 63/402,597, filedAug. 31, 2022, and U.S. Provisional Patent Application No. 63/356,955,filed Jun. 29, 2022, the contents of which are incorporated herein byreference as if fully disclosed herein.

TECHNICAL FIELD

Embodiments described herein relate to non-contact respiration sensing,and in particular to non-contact respiration sensing usinginterferometric sensors.

BACKGROUND

Wearable devices such as smart watches, smart eyewear, virtual and/oraugmented reality headsets, and the like, may include various sensors,which may sense physical phenomena such as movement, environmentalconditions, and biometric data about a user. The data from sensors in awearable device may be used to provide valuable information to a user,such as information about the activity and/or health of the user.Additional sensors in wearable devices may provide more robustinformation to a user and/or control or unlock additional applicationsof the wearable device. Given the wide range of applications for sensorsin wearable devices, any new development in the configuration oroperation of the sensors therein can be useful. New developments thatmay be particularly useful are developments that provide additionalsensing capability while maintaining a small form factor.

SUMMARY

Embodiments described herein relate to non-contact respiratory sensing.In one aspect, a head mounted device may include a housing and one ormore interferometric sensors disposed in the housing. The one or moreinterferometric sensors may be configured to emit electromagneticradiation towards an expected airflow path for respiration of a user andgenerate one or more interferometric signals including information aboutparticle movement in the expected airflow path for respiration of theuser.

In one aspect, the head mounted device may further include processingcircuitry communicably coupled to the one or more interferometricsensors and configured to determine respiration information about theuser based on the one or more interferometric signals. In variousaspects, the respiration information may include one or more ofrespiration rate, respiration velocity, respiration volume, respirationquality, whether a user is breathing through a nose or a mouth,information about particles inhaled, and information about particlesexhaled.

In various embodiments, the one or more interferometric sensors may beself-mixing interferometric (SMI) sensors or Mach-Zender interferometric(MZI) sensors.

In one aspect, the head mounted device may further include one or morereference interferometric sensors. The one or more referenceinterferometric sensors may be configured to emit electromagneticradiation towards an area outside the expected airflow path forrespiration of the user and generate one or more referenceinterferometric signals including information about particle movement inthe area outside the expected airflow path for respiration of the user.The processing circuitry may be communicably coupled to the one or morereference interferometric sensors and configured to determine therespiration information about the user based on the one or moreinterferometric signals and the one or more reference interferometricsignals.

In one aspect, the one or more interferometric sensors comprise a firstinterferometric sensor and a second interferometric sensor. The firstinterferometric sensor may include one or more of a focal length, adepth of field, a numerical aperture, an angle of incidence with respectto a plane located in the expected airflow path for respiration of theuser, and one or more characteristics of the electromagnetic radiationemitted therefrom that is different from the second interferometricsensor.

In one aspect, the head mounted device comprises a display. Theprocessing circuitry may be coupled to the display and configured tocause the display to change in response to respiration of the user.

In one aspect, a method for operating a head mounted device may includegenerating, from a set of one or more interferometric sensors disposedin a housing of the head mounted device, one or more interferometricsignals including information about particle movement caused byrespiration of a user and determining, by processing circuitry in thehead mounted device, respiration information about the user based on theone or more interferometric signals.

In one aspect, the respiration information may include one or more ofrespiration rate, respiration velocity, respiration volume, respirationquality, whether a user is breathing through a nose or mouth,information about particles inhaled, and information about particlesexhaled.

In various aspects, the one or more interferometric sensors may be SMIsensors or MZI sensors.

In one aspect, the method further includes generating, from a set of oneor more reference interferometric sensors disposed in the housing of thehead mounted device, one or more reference interferometric signalsincluding information about particle movement that is not caused byrespiration of the user.

In one aspect, the respiration information about the user may bedetermined based on the one or more interferometric signals and the oneor more reference interferometric signals.

In one aspect, a head mounted device may include a housing, one or moreinterferometric sensors, and a plurality of electromagnetic radiationdetectors. The one or more interferometric sensors may be disposed inthe housing and configured to emit electromagnetic radiation towards anexpected airflow path for respiration of a user and generate one or moreinterferometric signals including information about particle movement inthe expected airflow path for respiration of the user. The plurality ofelectromagnetic radiation detectors may be distributed in the housingand configured to generate one or more detector signals includinginformation about reflections of the electromagnetic radiation emittedfrom the one or more interferometric sensors from one or more particlesin the expected airflow path for respiration of the user.

In one aspect, the head mounted device may further include processingcircuitry communicably coupled to the one or more interferometricsensors and the one or more electromagnetic radiation detectors. Theprocessing circuitry may be configured to determine a particle size ofone or more particles in the expected airflow path for respiration ofthe user based on the one or more interferometric signals and the one ormore detector signals.

In one aspect, the processing circuitry may be further configured todetermine respiration information about the user based on the one ormore interferometric signals and the one or more detector signals.

In one aspect, the respiration information includes one or more ofrespiration rate, respiration velocity, respiration volume, respirationquality, whether a user is breathing through a nose or a mouth,information about particles inhaled, and information about particlesexhaled.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to representative embodiments illustrated inthe accompanying figures. It should be understood that the followingdescriptions are not intended to limit this disclosure to one includedembodiment. To the contrary, the disclosure provided herein is intendedto cover alternatives, modifications, and equivalents as may be includedwithin the spirit and scope of the described embodiments, and as definedby the appended claims.

FIG. 1 shows an example electrical block diagram of a wearable device,such as described herein.

FIGS. 2A and 2B show an anatomical views of a nose, such as describedherein.

FIG. 3 shows an exemplary wearable device being worn by a user, such asdescribed herein.

FIG. 4 shows an exemplary wearable device being worn by a user, such asdescribed herein.

FIGS. 5A and 5B show an exemplary wearable device being worn by a user,such as described herein.

FIG. 6 is a flow diagram illustrating a method of operating a wearabledevice, such as described herein.

FIG. 7 is a flow diagram illustrating a method of operating a wearabledevice, such as described herein.

FIG. 8 shows an example electrical block diagram of a wearable device,such as described herein.

FIGS. 9-12 show an exemplary wearable device being worn by a user, suchas described herein.

FIGS. 13A through 13C show various configurations for interferometricsensors, such as described herein.

FIG. 14 is a flow diagram illustrating a method of operating a wearabledevice, such as described herein.

FIG. 15 is an example electrical block diagram of a wearable device,such as described herein.

The use of the same or similar reference numerals in different figuresindicates similar, related, or identical items.

The use of cross-hatching or shading in the accompanying figures isgenerally provided to clarify the boundaries between adjacent elementsand also to facilitate legibility of the figures. Accordingly, neitherthe presence nor the absence of cross-hatching or shading conveys orindicates any preference or requirement for particular materials,material properties, element proportions, element dimensions,commonalities of similarly illustrated elements, or any othercharacteristic, attribute, or property for any element illustrated inthe accompanying figures.

Additionally, it should be understood that the proportions anddimensions (either relative or absolute) of the various features andelements (and collections and groupings thereof) and the boundaries,separations, and positional relationships presented therebetween, areprovided in the accompanying figures merely to facilitate anunderstanding of the various embodiments described herein and,accordingly, may not necessarily be presented or illustrated to scale,and are not intended to indicate any preference or requirement for anillustrated embodiment to the exclusion of embodiments described withreference thereto.

DETAILED DESCRIPTION

Coherent optical sensing, including Doppler velocimetry andheterodyning, can be used to measure physical phenomena includingpresence, distance, velocity, size, surface properties, and particlecount. Interferometric sensors such as SMI sensors and MZI sensors maybe used to perform coherent optical sensing. An SMI sensor is definedherein as a sensor that is configured to generate and emit light from aresonant cavity of a semiconductor light source, receive a reflection orbackscatter of the light (e.g., light reflected or backscattered from anobject) back into the resonant cavity, coherently or partiallycoherently self-mix the generated and reflected/backscattered lightwithin the resonant cavity, and produce an output indicative of theself-mixing (i.e., an SMI signal). The generated, emitted, and receivedlight may be coherent or partially coherent, but a semiconductor lightsource capable of producing such coherent or partially coherent lightmay be referred to herein as a coherent light source. The generated,emitted, and received light may include, for example, visible orinvisible light (e.g., green light, infrared (IR) light, or ultraviolet(UV) light). The output of an SMI sensor (i.e., the SMI signal) mayinclude a photocurrent produced by a photodetector (e.g., a photodiode).Alternatively or additionally, the output of an SMI sensor may include ameasurement of a current or junction voltage of the SMI sensor'ssemiconductor light source.

Generally, an SMI sensor may include a light source and, optionally, aphotodetector. The light source and photodetector may be integrated intoa monolithic structure. Examples of semiconductor light sources that canbe integrated with a photodetector include vertical cavitysurface-emitting lasers (VCSELs), edge-emitting lasers (EELs),horizontal cavity surface-emitting lasers (HCSELs), verticalexternal-cavity surface-emitting lasers (VECSELs), quantum-dot lasers(QDLs), quantum cascade lasers (QCLs), and light-emitting diodes (LEDs)(e.g., organic LEDs (OLEDs), resonant-cavity LEDs (RC-LEDs), micro LEDs(mLEDs), superluminescent LEDs (SLEDS), and edge-emitting (ELEDs). Theselight sources may also be referred to as coherent light sources. Asemiconductor light source may be integrated with a photodetector in anintra-cavity, stacked, or adjacent photodetector configuration toprovide an SMI sensor.

Generally, SMI sensors have a small footprint and are capable ofmeasuring myriad physical phenomena. Accordingly, they are useful inwearable devices, which are generally limited in size. As discussedabove, a portion of the functionality of many wearable devices isdirected to the measurement of biometric data about a user, such asheart rate and respiration rate. The small footprint of SMI sensors mayenable additional sensing opportunities by allowing sensors to be placedin previously impractical locations, while the high accuracy of SMIsensors may enable the determination of rich biometric data.

MZI sensors are similar to SMI sensors, except that they include anelectromagnetic radiation detector that is separate from anelectromagnetic radiation source, and include an optical elementconfigured to split electromagnetic radiation from the electromagneticradiation source into a sensing portion and a feedback portion. Thesensing portion of electromagnetic radiation is directed towards adesired target, where it is reflected and/or backscattered therefrom.The optical element is configured so that the reflected and/orbackscattered part of sensing portion is mixed with the feedbackportion. In some applications, an MZI sensor includes a balancedelectromagnetic radiation detector that receives the reflected and/orbackscattered part of the sensing portion and the feedback portion atdifferent electromagnetic radiation detectors. The MZI sensor providesan interferometric output signal based on the mixed feedback portion andthe reflected and/or backscattered part of the sensing portion.

As described in various embodiments herein, SMI sensors, or any othertype of interferometric sensor, may be used to determine biometric datasuch as movement, and in particular muscle, ligament, tendon, and/orskin movement, and respiratory information such as respiration rate,respiration quality, information about nasal congestion, informationabout snoring, airflow velocity, and breathing volume. Placing andorienting SMI sensors in a head-mounted device so that they emitelectromagnetic radiation towards an anatomical structure adjacent to anasal passageway of a user may allow for the accurate determination ofrespiration information based on movement of the anatomical structure.For example, placing and orienting SMI sensors over a portion of thenose of the user may allow a head-mounted device such as smart eyewear,a virtual and/or augmented reality headset, a smart face-mask, and/or asmart nose clip to determine respiration information about a user.

SMI sensors may additionally or alternatively be used to detectintentional or unintentional movement of the face and/or nose of theuser. Detection of unintentional facial movements may provide datauseful for the diagnosis or monitoring of a health condition. Detectionof intentional movements may be used to control various aspects of adevice, such as navigating a user interface thereof.

Nasal and/or eye tissue, for example, of users can have varioussensitivities, such as allergies, abrasion sensitivities, sensor and/orenergy exposure sensitivities, etc. Accordingly, in some aspectsdescribed herein SMI sensors may be operated to emit electromagneticradiation for sensing only when it is determined to be appropriate. Forexample, SMI sensors may be operated to emit electromagnetic radiationwhen they are in contact with a user's skin or the electromagneticradiation emitted therefrom is otherwise unlikely to be directed at ortowards a user's eyes. Accordingly, wearable devices described hereinmay detect when it is appropriate to emit electromagnetic radiation froma particular SMI sensor or sensors and enable and disable the emissionof electromagnetic radiation therefrom accordingly.

Additionally, SMI sensors, MZI sensors, or any other type ofinterferometric sensor, may be used to determine respiration informationsuch as respiration rate, respiration velocity, respiration volume,respiration quality, whether a user is breathing through their nose ormouth, information about particles inhaled (e.g., particle size,particle count), and information about particles exhaled (e.g., particlesize, particle count). In particular, sensors may be positioned andoriented in a head-mounted device to emit electromagnetic radiationtowards an expected airflow path for respiration of a user, and generateone or more interferometric signals including information about particlemovement in the area. As discussed herein, particles may be liquidmatter or solid matter. Further as discussed herein, airflow is agaseous flow that may carry particles. The one or more interferometricsignals may be used to determine the aforementioned respirationinformation, as well as additional information. In some aspects,multiple interferometric sensors may be positioned and oriented in ahead mounted device in order to differentiate between nose and mouthbreathing of a user, as well as to differentiate between airflow due torespiration of a user and ambient airflow in the environment in whichthe user is located.

The foregoing and other embodiments are discussed below with referenceto FIGS. 1-15 . However, those skilled in the art will readilyappreciate that the detailed description given herein with respect tothese figures is for explanation only and should not be construed aslimiting.

Directional terminology, such as “top”, “bottom”, “upper”, “lower”,“front”, “back”, “over”, “under”, “above”, “below”, “left”, or “right”is used with reference to the orientation of some of the components insome of the figures described below. Because components in variousembodiments can be positioned in a number of different orientations,directional terminology is used for purposes of illustration only and isusually not limiting. The directional terminology is intended to beconstrued broadly, and therefore should not be interpreted to precludecomponents being oriented in different ways. Also, as used herein, thephrase “at least one of” preceding a series of items, with the term“and” or “or” to separate any of the items, modifies the list as awhole, rather than each member of the list. The phrase “at least one of”does not require selection of at least one of each item listed; rather,the phrase allows a meaning that includes at a minimum one of any of theitems, and/or at a minimum one of any combination of the items, and/orat a minimum one of each of the items. By way of example, the phrases“at least one of A, B, and C” or “at least one of A, B, or C” each referto only A, only B, or only C; any combination of A, B, and C; and/or oneor more of each of A, B, and C. Similarly, it may be appreciated that anorder of elements presented for a conjunctive or disjunctive listprovided herein should not be construed as limiting the disclosure toonly that order provided.

FIG. 1 shows an exemplary wearable device 100. The wearable device 100includes a housing 102, a number of sensors 104 disposed in the housing102, processing circuitry 106 communicably coupled to the sensors 104,and a display 108, which is also communicably coupled to the processingcircuitry 106. The sensors 104 may include a number of SMI sensors 104-1and a proximity sensor 104-2. While two SMI sensors 104-1 and oneproximity sensor 104-2 are shown for purposes of illustration, thewearable device 100 may include any number of SMI sensors 104-1 and anynumber of proximity sensors 104-2. Further, the wearable device 100 mayinclude any number of additional sensors, which are not shown. Asdiscussed herein, the sensors 104 may be positioned and oriented in thehousing 102 to emit electromagnetic radiation towards an anatomicalstructure adjacent a nasal passageway of the user. For example, thesensors 104 may be positioned and oriented to be over or otherwise nearthe nose of the user when the wearable device 100 is being worn. Thedisplay 108 may be positioned to be in front an eye of the user. In someaspects of the present disclosure, two displays 108 may be provided, onein front of each eye of the user. In another aspect, the wearable device100 does not include a display, and the user may interact with thewearable device 100 using a non-visual user interface (e.g., voicecontrol) or interact with the wearable device 100 via a device that iscommunicably coupled to the wearable device 100 (e.g., via a wired orwireless connection).

The SMI sensors 104-1 may be operated to emit electromagnetic radiationtoward an anatomical structure of the user adjacent a nasal passageway.For example, the SMI sensors 104-1 may be positioned and oriented toemit electromagnetic radiation toward tissue adjacent, surrounding, orotherwise near the nasal passageway of the user. The tissue may be boneor soft tissue. For example, the SMI sensors 104-1 may be positioned andoriented to emit electromagnetic radiation towards a nasal bone of theuser, an upper lateral cartilage of the nose of the user, a lowerlateral cartilage of the nose the user, and/or the skin on and/or aroundthe nose of the user. The SMI sensors 104-1 may be positioned andoriented to be directly against the skin of the user, or there may be anair gap present between the SMI sensors 104-1 and the skin of the user.The electromagnetic radiation emitted from the SMI sensors 104-1 may beconfigured to reflect and/or backscatter from the tissue of the user orpenetrate the tissue of the user to a desired depth, passing throughsome tissue (e.g., skin) with minimal or low reflection and/orbackscatter, while reflecting and/or backscattering off other tissue(e.g., cartilage or bone) to a greater degree. For example, somecharacteristics of the electromagnetic radiation (e.g., wavelength)and/or a focal length of the SMI sensors 104-1 may be configured tomeasure movement of a desired anatomical structure. In some aspects,different ones of the SMI sensors 104-1 may be configured to emitelectromagnetic radiation that reflects and/or backscatters primarilyfrom different anatomical structures, either by the position andorientation of the SMI sensors 104-1 in the housing 102, or by thecharacteristics of the electromagnetic radiation emitted therefrom.

The electromagnetic radiation emitted from the SMI sensors 104-1 may bemodulated or non-modulated. The modulation, or lack of modulation, ofthe electromagnetic radiation may allow for the detection of differentphysical phenomena. For example, a first modulation pattern of theelectromagnetic radiation emitted from the SMI sensors 104-1 may beuseful for detecting the proximity of an object to the SMI sensors104-1, while a second modulation pattern of the electromagneticradiation emitted from the SMI sensors 104-1 may be useful for detectingmovement (e.g., velocity) of an object. In various aspects, the SMIsensors 104-1 may be operated such that the electromagnetic radiationemitted therefrom is modulated in the same or different ways in order todetect desired physical phenomena.

The electromagnetic radiation emitted from an SMI sensor 104-1 may bepartially reflected and/or backscattered from a desired anatomicalstructure back towards the SMI sensor 104-1. The reflected and/orbackscattered electromagnetic radiation may self-mix (or interfere) withthe generated electromagnetic radiation. The self-mixing may be measured(e.g., by measuring the electromagnetic radiation with a photodetectoror by measuring a current and/or junction voltage of a light source ofthe SMI sensor 104-1) to generate an SMI signal. By generating theelectromagnetic radiation via specific drive patterns (e.g., via dopplerand/or triangular drive patterns) and measuring the reflection and/orbackscatter thereof, SMI signals may include information about movementof the desired anatomical structure.

The proximity sensor 104-2 may detect the proximity of the wearabledevice 100 to the user, which is indicated in a proximity signalprovided to the processing circuitry 106. The proximity sensor 104-2 maybe any suitable type of proximity sensor, such as, for example, anultrasonic sensor, an infrared sensor, a capacitive sensor, or aresistive sensor. In general, it may be desirable for the proximitysensor 104-2 to be a type of proximity sensor that prevents the SMIsensor 104-1 from emitting electromagnetic radiation, as discussedherein.

As discussed above, the desired anatomical structure may be adjacent anasal passageway of the user. For example, the desired anatomicalstructure may be the nasal bone, the upper lateral cartilage of thenose, the lower lateral cartilage of the nose, and/or the skin on and/oraround the nose. The processing circuitry 106 may use the informationabout movement of the desired anatomical structure in the SMI signals todetermine respiration information about the user. For example, theprocessing circuitry 106 may use the information about movement of thedesired anatomical structure to determine respiration rate, respirationquality, information about nasal congestion (e.g., a degree of nasalcongestion), information about snoring (e.g., the presence or absence ofsnoring, a severity of snoring), airflow velocity, and breathing volume.The processing circuitry 106 may determine respiration information fromthe SMI signals in any suitable manner, such as, for example, byproviding the SMI signals to a machine learning model.

In addition to respiration information, the processing circuitry 106 mayalso use the SMI signals to determine voluntary or involuntary facialmovements of the user. For example, the processing circuitry 106 may usethe SMI signals to detect facial tics of a user, which may provideinformation for the diagnosis or monitoring of some health conditions.Additionally, the processing circuitry 106 may use the SMI signals todetect intentional facial movements, such as a movement of the nose.Detected intentional facial movements may be used, for example, as auser input to the wearable device 100. For example, intentional facialmovements of the user, in addition to other types of user input, may beused to change or otherwise navigate a user interface shown on thedisplay 108 of the wearable device 100. Notably, the display 108 may beomitted in some aspects and intentional facial movements may be used asa user input to control or otherwise operate the wearable device 100 inany suitable manner.

While not shown, the wearable device 100 may include any number of userinput elements such as buttons, microphones, speakers, or the like. Thewearable device 100 may also include additional structural elements suchas straps, bands, or other suitable elements for positioning, attaching,or securing the wearable device 100 to the user. The wearable device 100may also include additional circuitry, such as additional sensors,communication circuitry (e.g., wired or wireless communicationcircuitry), or any other circuitry to facilitate the operation andfunctionality of the wearable device 100.

The wearable device 100 may be a head-mounted device. Accordingly, thehousing 102 of the wearable device 100 may be shaped and sized to bemounted to the head of a user. One or more straps or other mountingstructures (not shown) may be used to affix the wearable device 100 tothe head of the user. In various aspects discussed herein, the housing102 may be sized and shaped to provide eyewear, a virtual and/oraugmented reality headset, a face mask, and a nose clip. However, theform factor of the wearable device 100 may be provided in any suitableshape and size without departing from the principles herein.

FIGS. 2A and 2B show anatomical views of a nose 200 of a user. Inparticular, FIG. 2A shows an anatomical view of a nose of a user along asagittal plane, while FIG. 2B shows an anatomical view of a nose of auser along a frontal plane. The nose 200 includes a nasal bone 202, anupper lateral cartilage 204, and a lower lateral cartilage 206. Thenasal bone 202, upper lateral cartilage 204, and lower lateral cartilage206 are covered with skin 208. In various aspects of the presentdisclosure, SMI sensors such as those discussed herein may be positionedand oriented in a wearable device such that they emit electromagneticradiation towards one or more of the nasal bone 202, the upper lateralcartilage 204, the lower lateral cartilage 206, and the skin 208 on oraround the nose 200. Movement of any one of the nasal bone 202, theupper lateral cartilage 204, the lower lateral cartilage 206, and theskin 208 on or around the nose 200 may be indicative of variousrespiration information about the user such as respiration rate,respiration quality, information about nasal congestion (e.g., a degreeof nasal congestion), information about snoring (e.g., the presence orabsence of snoring, severity of snoring), airflow velocity, andbreathing volume. As discussed herein, the electromagnetic radiationemitted from the SMI sensors may be configured (e.g., via wavelength,focal length, etc.) to primarily reflect and/or backscatter from aparticular one of the aforementioned anatomical structures, or any otheranatomical structure, and measured to generate SMI signals that are usedto determine the respiration information. Further, the SMI signals maybe used to detect voluntary and involuntary nose and/or facialmovements.

FIG. 3 shows a wearable device 300 being worn by a user according to anadditional aspect of the present disclosure. The wearable device 300shown in FIG. 3 is in the form factor of eyewear, and thus may include aframe 302, a pair of lenses 304, and a number of sensors 306, which maybe positioned and oriented in nosepieces 308 coupled to the frame 302such that they are over or near the nose of the user. An enlarged viewof the nosepieces 308 including the sensors 306 is shown in FIG. 3 . Thesensors 306 may be positioned and oriented so that they emitelectromagnetic radiation towards an anatomical structure adjacent anasal passageway of the user. The sensors 306 may be positioned andoriented in the nosepieces 308 such that they are in direct contact withthe skin of the user or such that there is an air gap between thesensors 306 and the skin of the user. The sensors 306 may be SMI sensorsor include at least one SMI sensor along with one or more other types ofsensors, such as a proximity sensor. The sensors 306 may be operated asdiscussed herein to detect movement of an anatomical structure of auser, determine respiration information about the user, detectintentional and/or unintentional facial movements of the user, andoperate appropriately to avoid irritating a user. While the nosepieces308 are shown as separate pieces coupled to the frame 302, in someaspects the nosepieces 308 may be molded into or otherwise integratedwith the frame 302. While not shown, the wearable device 300 may includea display, which may be projected or otherwise provided on one or bothof the lenses 304. In some aspects, the wearable device 300 may notinclude a display. Further, the wearable device 300 may includeprocessing circuitry to operate the sensors 306 as discussed herein,additional circuitry, additional user input elements such as buttons,microphones, speakers, and cameras, and/or additional structuralelements. In general, FIG. 3 is meant to illustrate an exemplary formfactor of a wearable device 300 as discussed herein, as well as theplacement of sensors 306 in the exemplary form factor.

FIG. 4 shows a wearable device 400 being worn by a user according to anadditional aspect of the present disclosure. The wearable device 400shown in FIG. 4 is in the form factor of a face mask, and thus mayinclude a cover 402, a number of straps 404 coupled to the cover 402 andconfigured to attach the cover 402 over the nose and/or mouth of theuser, and a number of sensors 406 disposed in the cover 402. The sensors406 may be positioned and oriented to be over or near the nose of theuser. In particular, the sensors 406 may be positioned and oriented toemit electromagnetic radiation towards an anatomical structure adjacenta nasal passageway of the user. In various aspects, the sensors 406 maybe in direct contact with the skin of the user or there may be an airgap between the sensors 406 and the skin of the user. The sensors 406may be SMI sensors or include at least one SMI sensor along with one ormore other types of sensors, such as a proximity sensor. The sensors 406may be operated as discussed herein to detect movement of an anatomicalstructure of a user, determine respiration information about the user,detect intentional and/or unintentional facial movements of the user,and operate appropriately to avoid irritating a user. While not shown,the wearable device 400 may include additional components such as adisplay, processing circuitry to operate the sensors 406 as discussedherein, additional circuitry, additional user input elements such asbuttons, microphones, speakers, and cameras, and/or additionalstructural elements. In general, FIG. 4 is meant to illustrate anexemplary form factor of a wearable device 400 as discussed herein, aswell as the placement of sensors 406 in the exemplary form factor.

FIGS. 5A and 5B show a wearable device 500 being worn by a useraccording to an additional embodiment of the present disclosure. Inparticular, FIG. 5A shows a front view and FIG. 5B shows a side view ofthe wearable device 500 being worn by the user. The wearable device 500shown in FIGS. 5A and 5B is in the form factor of a virtual and/oraugmented reality headset, and thus may include a housing 502, a strap504 for attaching the housing 502 to the head of the user, and a numberof sensors 506 disposed in the housing 502. The sensors 506 may bepositioned and oriented to be over or near the nose of the user. Inparticular, the sensors 506 may be positioned and oriented to emitelectromagnetic radiation towards an anatomical structure adjacent anasal passageway of the user. In various aspects, the sensors 506 may bein direct contact with the skin of the user or there may be an air gapbetween the sensors 506 and the skin of the user. The sensors 506 may beSMI sensors or include at least one SMI sensor along with one or moreother types of sensors, such as a proximity sensor. The sensors 506 maybe operated as discussed herein to detect movement of an anatomicalstructure of a user, determine respiration information about the user,detect intentional and/or unintentional facial movements of the user,and/or operate appropriately to avoid irritating a user. While notshown, the wearable device 500 may include additional components such asdisplays, processing circuitry to operate the displays and sensors 506as discussed herein, additional circuitry, additional user inputelements such as buttons, microphones, speakers, and cameras, and/oradditional structural elements. In general, FIGS. 5A and 5B are meant toillustrate an exemplary form factor of a wearable device 500 asdiscussed herein, as well as the placement of sensors 506 in theexemplary form factor.

While FIGS. 3-5B illustrate various exemplary form factors of a wearabledevice, they are not meant to be exhaustive. The present disclosurecontemplates any form factor for a wearable device capable ofpositioning SMI sensors as discussed herein, including swimming goggles,safety eyewear, or any other suitable form factor.

As discussed herein, SMI sensors may be placed over or near the nose ofa user to determine valuable information such as respiration informationas well as voluntary or involuntary nose and/or facial movements. Insome instances, some users may be especially sensitive toelectromagnetic radiation, and thus placing SMI sensors in closeproximity to the eyes of the user may require additional considerations.Accordingly, FIG. 6 is a flow diagram illustrating a method of operatinga wearable device according to one aspect of the present disclosure. Oneor more SMI signals are received from one or more SMI sensors (step600). Additionally or alternatively, one or more proximity signals arereceived from one or more proximity sensors (step 602). The one or moreSMI signals and/or the one more proximity signals are used by processingcircuitry of the wearable device to determine if it is appropriate toemit electromagnetic radiation from the one or more SMI sensors (step604). Determining if it is appropriate to emit electromagnetic radiationfrom the one or more SMI sensors may include determining if the wearabledevice is being worn by the user, or is being properly worn by the user(e.g., the SMI sensors and/or proximity sensors are directly against theskin of the user). Such a determination may be accomplished in anysuitable manner, including comparing the SMI signals and/or proximitysignals to a threshold value, making calculations based on the SMIsignals and/or proximity signals, providing the SMI signals and/orproximity signals to a machine learning model, etc. If it is appropriateto emit electromagnetic radiation from the one or more SMI sensors, theprocessing circuitry may enable the emission of electromagneticradiation from the one or more SMI sensors (step 606). Alternatively, ifit is not appropriate to emit electromagnetic radiation from the one ormore SMI sensors or there is not sufficient information from theproximity sensor, the processing circuitry may disable the emission ofelectromagnetic radiation from the one or more SMI sensors (step 608).

The foregoing process may be repeated at a predetermined interval, orinitiated in response to a detected event such as significant movementof the wearable device, which may be detected by one or more additionalsensors such as an accelerometer. Operating the SMI sensors of awearable device in this manner may improve the safety profile, batterylife, and/or efficacy of the device. The principles of operationdescribed with respect to FIG. 6 may be used in any of the wearabledevices described herein.

The wearable devices discussed herein may determine respirationinformation about a user based on SMI sensors positioned on or near thenose of the user. However, the present disclosure contemplates thebroader use of information about movement of tissue near a respiratorypathway of a user to determine respiration information about the user.To illustrate these principles, FIG. 7 is a flow diagram describing amethod for operating a wearable device to obtain respiration informationabout a user according to one aspect of the present disclosure. First,one or more SMI signals are generated, where the one or more SMI signalsinclude information about the movement of tissue near a respiratorypathway of a user (step 700). The movement of the tissue may be avibration of the tissue. The tissue may be soft tissue such as skin,cartilage, muscle, tendon, or ligament, or hard tissue such as bone. Theone or more SMI signals may be generated from one or more SMI sensors inthe wearable device. The one or more SMI sensors may be positioned andoriented to be over or near the respiratory pathway of the user. Therespiratory pathway may be a nasal passageway of the user.

Next, respiration information about the user is determined based on theone or more SMI signals (step 702). The respiration information may bedetermined, for example, by providing the one or more SMI signals to amachine learning model. In general, any suitable calculation,transformation, or the like may be performed to determine therespiration information from the one or more SMI signals. Therespiration information may include one or more of respiration rate,respiration quality, information about nasal congestion (i.e., degree ofnasal congestion), information about snoring (e.g., presence or absenceof snoring, severity of snoring), airflow velocity, and breathingvolume. The respiration information may be useful to the user for thediagnosis or monitoring of some health conditions. In some aspects, therespiration information may be displayed graphically for the user. Thewearable device may use the respiration information to notify the userof certain events, such as when the user is experiencing a particularlevel of nasal congestion (which may be indicative of seasonal allergiesand/or illness), when the user is breathing through the mouth ratherthan the nose, etc. Further, visualizations of the user's breathing maybe generated and shown to the user, which may aid in activities such asguided breathing instruction or biofeedback. If it is detected that auser stops breathing, emergency services can be contacted to providemedical aid, in some cases automatically. The principles of operationdescribed with respect to FIG. 7 may be used in any of the wearabledevices described herein.

In addition to determining respiration information, data from SMIsensors positioned and oriented to be over or near a respiratory pathwaymay be used along with complimentary data streams from other sensors toobtain or discern additional information about a user. The other sensorsmay be located in the wearable device itself, in a different wearabledevice worn by the user, in a wearable device worn by another user, orin a non-wearable device. For example, data from a wrist-worn wearabledevice worn by the user may be combined with data from SMI sensors in awearable device as described herein to obtain additional informationabout the user. Further, data from a non-wearable device, such as adevice in the environment around a user may be combined with data fromSMI sensors in a wearable device as described herein to obtainadditional information about the user. Data from a wearable device wornby a different user may also be combined with data from SMI sensors in awearable device as described herein to enable additional functionality(e.g., improved gaming experiences between users). In one example, bloodoxygen saturation information from a blood oxygen saturation sensor in awearable device worn by the user may be combined with respirationinformation obtained as discussed herein. The blood oxygen saturationinformation may enrich the respiration information to enable discernmentof respiration events such as a user holding their breath versus a userchoking or drowning. Gaze tracking information may be combined withrespiration information to determine information about a user such asattentiveness and focus on a task (e.g., student or driver focus), whichmay enable a user to be notified to take a break as attentiveness wanes.Respiration information, alone or combined with other information abouta user, may enable a wearable device to provide breathing queues (e.g.,when to breathe in, when to hold breath, when to breathe out, andbreathing pacing), either for general health or related to a particulartask such as for improving performance in sporting or other activities(e.g., swimming, diving, golf, tennis, archery, and baseball).

Respiration information, along with other complimentary information, mayalso be used to track a user's breathing or health trends over time.Such information may be indicative of training capacity and whether aparticular training regimen is effective for a user. Respirationinformation, along with other complimentary information, may alsoprovide an unobtrusive way to monitor an emotional response of a user,for example, by detecting gasping, laughter, crying, sobbing, speech andspeech emphasis, etc. Monitoring emotional response via respirationinformation may be less obtrusive than directly monitoring audio.Emotional response information may in turn be useful in determining auser's response to various environmental stimuli or medications, which auser may wish to track over time.

While FIGS. 1-7 primarily discuss the use of SMI sensors to determinerespiration information and/or movement information in the context of awearable device, any interferometric sensors, such as MZI sensors, canbe used to achieve similar results. Further, interferometric sensors maybe positioned and oriented in a housing of a wearable device to measureother physical phenomena. In one aspect, interferometric sensors may bepositioned and oriented in a wearable device to detect respiration of auser without contact. In particular, interferometric sensors may bepositioned and oriented in a housing of a head mounted device to senseparticle movement caused by respiration of a user. FIG. 8 shows anexemplary wearable device 800 configured in this manner. The wearabledevice 800 includes a housing 802, a number of sensors 804 disposed inthe housing 802, processing circuitry 806 communicably coupled to thesensors 804, and an optional display 808, which is also communicablycoupled to the processing circuitry 806. The sensors 804 may include anumber of interferometric sensors 804-1 and, optionally, one or moreelectromagnetic radiation detectors 804-2. While two interferometricsensors 804-1 and one electromagnetic radiation detector 804-2 are shownfor purposes of illustration, the wearable device 800 may include anynumber of interferometric sensors 804-1 and any number ofelectromagnetic radiation detectors 804-2. Further, the wearable device800 may include any number of additional sensors, which are not shown.As discussed herein, the interferometric sensors 804-1 may be positionedand oriented in the housing 802 to emit electromagnetic radiationtowards an expected airflow path for respiration of a user. For example,the sensors 804-1 may be positioned and oriented to emit electromagneticradiation towards an area in front of the mouth of a user, and/or belowa nose of the user where air would normally flow during respiration. Thedisplay 808 may be positioned to be in front of an eye of the user. Insome aspects, two displays 808 may be provided, one in front of each eyeof the user. In another aspect, the wearable device 800 does not includea display, and the user may interact with the wearable device 800 usinga non-visual user interface (e.g., voice control) or interact with thewearable device 800 via a device that is communicably coupled to thewearable device 800 (e.g., via a wired or wireless connection).

The electromagnetic radiation emitted from the interferometric sensors804-1 may be modulated or non-modulated. The modulation, or lack ofmodulation, of the electromagnetic radiation may allow for the detectionof different physical phenomena. For example, a first modulation patternof electromagnetic radiation emitted from the interferometric sensors804-1 may be useful for detecting the proximity of an object to theinterferometric sensors 804-1, while a second modulation pattern of theelectromagnetic radiation emitted from the interferometric sensors 804-1may be useful for detecting movement (e.g., velocity) of an object. Invarious aspects, the interferometric sensors 804-1 may be operated suchthat the electromagnetic radiation emitted therefrom is modulated in thesame or different ways in order to detect desired physical phenomena. Inone aspect, the electromagnetic radiation emitted from theinterferometric sensors 804-1 is modulated in a frequency modulatedcontinuous wave (FMCW) mode, wherein the instantaneous frequency of theelectromagnetic radiation is swept during signal integration.

The interferometric sensors 804-1 may each be configured with aparticular focal length, depth of field, numerical aperture, angle ofincidence (e.g., with respect to a reference plane), wavelength ofelectromagnetic radiation emitted, and modulation of electromagneticradiation emitted. In some aspects, at least one of the focal length,depth of field, numerical aperture, angle of incidence, wavelength ofelectromagnetic radiation emitted, and modulation of electromagneticradiation emitted, are different between the interferometric sensors804-1.

The electromagnetic radiation emitted from an interferometric sensor804-1 may be partially reflected and/or backscattered from particles inthe expected airflow path for respiration of the user back towards theinterferometric sensor 804-1. The reflected and/or backscatteredelectromagnetic radiation may be mixed with a reference signal (asdiscussed with respect to SMI and MZI sensors herein) to produce aninterferometric signal that is indicative of particle movement in thearea. By generating the electromagnetic radiation via specific drivepatterns (e.g., via doppler and/or triangular drive patterns) andmeasuring the reflection and/or backscatter thereof, interferometricsignals may include information about respiration of the user.

The one or more electromagnetic radiation detectors 804-2 may bepositioned and oriented in the housing 802 to sense off-axis reflectionsand/or backscattering of electromagnetic radiation emitted by theinterferometric sensors 804-1. This may enable scatterometry forparticle size tracking of particles inhaled and/or exhaled by a user ofthe wearable device 800.

While not shown, the wearable device 800 may include any number of userinput elements such as buttons, microphones, speakers, and the like. Thewearable device 800 may also include additional structural elements suchas straps, bands, or other suitable elements for positioning, attaching,or securing the wearable device 800 to the user. The wearable device 800may also include additional circuitry, such as additional sensors,communication circuitry (e.g., wired or wireless communicationcircuitry), or any other circuitry to facilitate the operation andfunctionality of the wearable device 800.

The wearable device 800 may be head mounted device. Accordingly, thehousing 802 of the wearable device 800 may be shaped and sized to bemounted to the head of a user. One or more straps or other mountingstructures (not shown) may be used to affix the wearable device 800 tothe head of the user. In various aspects discussed herein, the housing802 may be sized and shaped to provide eyewear, a virtual and/oraugmented reality headset, a face mask, and a nose clip. However, theform factor of the wearable device 800 may be provided in any suitableshape and size without departing from the principles herein.

FIG. 9 shows a side view of a wearable device 900 being worn by a useraccording to one embodiment of the present disclosure. The wearabledevice 900 is in the form factor of a virtual and/or augmented realityheadset, and thus may include a housing 902, a strap 904 for attachingthe housing 902 to the head of the user, and an interferometric sensor906 disposed in the housing 902. The interferometric sensor 906 may bepositioned and oriented towards an area 908 in front of the mouth and/ornose of the user that is expected to experience airflow due torespiration of the user (i.e., an expected airflow path for respirationof the user) such that the interferometric sensor 906 emitselectromagnetic radiation towards the area 908 in which airflow due torespiration is expected. The interferometric sensor 906 may be operatedas discussed herein to detect movement of particles in the area 908experiencing airflow in order to determine respiration information aboutthe user. While not shown, the wearable device 900 may includeadditional components such as displays, processing circuitry to operatethe displays and interferometric sensors 906 as discussed herein,additional circuitry, additional user input elements such as buttons,microphones, speakers, and cameras, and/or additional structuralelements. In general, FIG. 9 is meant to illustrate an exemplary formfactor of a wearable device 900 as discussed herein, as well as theplacement of an interferometric sensor 906 in the exemplary form factor.

FIG. 10 shows a side view of the wearable device 900 being worn by theuser according to an additional embodiment of the present disclosure.The wearable device 900 shown in FIG. 10 is similar to that shown inFIG. 9 , but illustrates two interferometric sensors 906 and a referencesensor 910. The interferometric sensors 906 may be positioned andoriented in the housing 902 such that a first one of the interferometricsensors 906 emits electromagnetic radiation towards a first area 908-1in front of the mouth of the user, while a second one of theinterferometric sensors 906 emits electromagnetic radiation towards asecond area 908-2 in front of the nose of the user. The first area 908-1may experience airflow primarily due to mouth breathing of the user,while the second area 908-2 may experience airflow due to both nose andmouth breathing of the user. By positioning and orienting theinterferometric sensors 906 in this or a similar manner, the wearabledevice 900 may be able to differentiate nose and mouth breathing of theuser, which may be useful in some situations.

The reference sensor 910 may be positioned and oriented in the housing902 towards an area 912 outside of an expected airflow path forrespiration of the user. The reference sensor may also be aninterferometric sensor configured to emit electromagnetic radiationtowards the area 912 outside the expected airflow path for respirationof the user and thus may sense particle movement in this area 912.Particle movement in the area 912 outside the expected airflow path forrespiration of the user may be indicative of airflow (e.g., due to windor air conditioning) that is not involved in respiration, and thus mayenable more accurate determination of respiration information.

FIG. 11 shows a front view of the wearable device 900 being worn by theuser according to one embodiment of the present disclosure. As shown,the wearable device 900 may include interferometric sensors 906distributed in a symmetrical fashion about the nose of the user. Thereference sensor 910 is also shown.

FIG. 12 shows a front view of the wearable device 900 being worn by theuser according to an additional embodiment of the present disclosure.The wearable device 900 shown in FIG. 12 is similar to that shown inFIG. 11 , but further includes a number of electromagnetic radiationdetectors 914 distributed throughout the housing 902. As discussedherein, the electromagnetic radiation detectors 914 may sense off-axisreflections and/or backscatter of electromagnetic radiation emitted fromthe interferometric sensors 906 to enable scatterometry and thusparticle size detection.

Notably, the particular number and arrangement of interferometricsensors 906, reference sensors 910, and electromagnetic radiationdetectors 914 shown in FIGS. 9-12 are for purposes of illustration only,and are not meant to be exhaustive or limiting. In general, the wearabledevice 900 may include any number of interferometric sensors 906,reference sensors 910, and/or electromagnetic radiation detectors 914positioned and oriented in the housing in any configuration withoutdeparting from the principles of the present disclosure.

Further, the form factor of the wearable device 900 shown in FIGS. 9-12is meant to be illustrative and not exhaustive. The principles describedherein, including positioning and orienting interferometric sensors inthe housing of a wearable device to detect particle movement fromrespiration of a user and the subsequent applications thereof, may beapplied to wearable devices have any suitable form factor (e.g.,eyewear, face masks, goggles, safety glasses, or the like).

In some aspects, it may be useful to position and orient interferometricsensors so that the electromagnetic radiation emitted therefrompartially or completely overlaps within a desired area. This may improveaccuracy and/or reliability of measurements. FIGS. 13A through 13Cillustrate a number of exemplary configurations for interferometricsensors 1000 with respect to an area 1002 experiencing airflow due torespiration of a user. FIG. 13A shows a single interferometric sensor1000 emitting electromagnetic radiation towards the area 1002. FIG. 13Bshows two interferometric sensors 1000 that are not co-planar emittingelectromagnetic radiation such that the electromagnetic radiationoverlaps within the area 1002. FIG. 13C shows three interferometricsensors 1000 that are co-planar emitting electromagnetic radiation thatdoes not overlap within the area 1002. As shown, an optic 1004 may beused to achieve this configuration. Notably, the configurations shown inFIGS. 13A through 13C are merely illustrative, and not exhaustive. Ingeneral, any number of interferometric sensors may be positioned andoriented to overlap the electromagnetic radiation emitted therefromwithin an area of interest, or not, in order to achieve a desiredeffect.

FIG. 14 is a flow diagram illustrating a method of operating a wearabledevice according to one aspect of the present disclosure. A set of oneor more interferometric signals is generated by one or moreinterferometric sensors in the wearable device (step 1100). The one ormore interferometric signals may include information about particlemovement due to respiration of the user. For example, the one or moreinterferometric signals may include information about particle movementdue to inhalation and/or exhalation through the mouth and/or nose of theuser. Accordingly, the one or more interferometric sensors may bepositioned and oriented in a housing of the wearable device to emitelectromagnetic radiation towards an expected airflow path forrespiration of the user, for example, in front of the nose and/or mouthof the user.

Next, respiration information about the user is determined based on theone or more interferometric signals (step 1102). The respirationinformation may be determined, for example, by providing the one or moreinterferometric signals to a machine learning model. In general, anysuitable calculation, transformation, estimation, or the like may beperformed on the interferometric signals to determine the respirationinformation therefrom. The respiration information may include one ormore of respiration rate, respiration velocity, respiration volume,respiration quality, whether a user is breathing through a nose or amouth, information about particles inhaled, and information aboutparticles exhaled. In some aspects, the respiration information may bedisplayed graphically for the user. The wearable device may use therespiration information to notify the user of certain events, such aswhen the user is experiencing a particular level of nasal congestion(which may be indicative of seasonal allergies and/or illness), when theuser is breathing through the mouth rather than the nose, etc. Further,visualizations of the user's breathing may be generated and shown to theuser, which may aid in activities such as guided breathing orbiofeedback. In some aspects, the user's breathing may be used as aninput for an application, such as for blowing out candles in a videogame. The user's breathing may also be used to generate feedback for auser in any suitable fashion, such as haptic feedback, audio alerts,visual alerts, or the like. If it is detected that a user stopsbreathing, emergency services can be contacted to provide medical aid,in some cases automatically. The principles of operation described withrespect to FIG. 14 may be used in any of the wearable devices describedherein.

Information from interferometric sensors discussed herein may be usedalong with complimentary data streams from other sensors (which may belocated on other devices) to obtain or discern additional informationabout a user or unlock additional applications. For example, data from awrist-worn device worn by the user may be combined with data from theinterferometric sensors discussed herein to obtain additionalinformation about the user. Further, data from a non-wearable device,such as a device in the environment around the user, may be combinedwith data from the interferometric sensors discussed herein to obtainadditional information about the user. Data from a wearable device wornby a different user may also be combined with data from interferometricsensors worn in a wearable device as described herein to enableadditional functionality (e.g., improved gaming experiences betweenusers). In one example, blood oxygen saturation information from a bloodoxygen saturation sensor in a wearable device worn by the user may becombined with respiration information obtained as discussed herein. Theblood oxygen saturation information may enrich the respirationinformation to enable discernment of respiration events such as a userholding their breath versus a user choking or drowning. Gaze trackinginformation may be combined with respiration information to determineinformation about a user such as attentiveness and focus on a task(e.g., student or driver focus), which may enable a user to be notifiedto take a break as attentiveness wanes. Respiration information, aloneor combined with other information about a user, may enable a wearabledevice to provide breathing queues (e.g., when to breathe in, when tohold breath, when to breathe out, and breathing pacing), either forgeneral health or related to a particular task such as for improvingperformance in sporting or other activities (e.g., swimming, diving,golf, tennis, archery, and baseball).

Respiration information, along with other complimentary information, mayalso be used to track a user's breathing or health trends over time.Such information may be indicative of training capacity and whether aparticular training regimen is effective for a user. Respirationinformation, along with other complimentary information, may alsoprovide an unobtrusive way to monitor an emotional response of a user,for example, by detecting gasping, laughter, crying, sobbing, speech andspeech emphasis, etc. Monitoring emotional response via respirationinformation may be less obtrusive than directly monitoring audio.Emotional response information may in turn be useful in determining auser's response to various environmental stimuli or medications, which auser may wish to track over time.

FIG. 15 shows a sample electrical block diagram of a wearable device1200, which may be implemented as any of the devices described withrespect to FIGS. 1, 3-5B, and 8-12 . The wearable device 1200 mayinclude an electronic display 1202 (e.g., a light-emitting display), aprocessor 1204 (also referred to herein as processing circuitry), apower source 1206, a memory 1208, or storage device, a sensor system1210, an input/output (I/O) mechanism 1212 (e.g., an input/outputdevice, input/output port, or haptic input/output interface). Theprocessor 1204 may control some or all of the operations of the wearabledevice 1200. The processor 1204 may communicate, either directly orindirectly, with some or all of the other components of the wearabledevice 1200. For example, a system bus or other communication mechanism1214 can provide communication between the electronic display 1202, theprocessor 1204, the power source 1206, the memory 1208, the sensorsystem 1210, and the I/O mechanism 1212.

The processor 1204 may be implemented as any electronic device capableof processing, receiving, or transmitting data or instructions, whethersuch data or instructions is in the form of software or firmware orotherwise encoded. For example, the processor 1204 may include amicroprocessor, central processing unit (CPU), an application-specificintegrated circuit (ASIC), a digital signal processor (DSP), acontroller, or a combination of such devices. As described herein, theterm “processor” or “processing circuitry” is meant to encompass asingle processing unit, multiple processors, multiple processing units,or other suitably configured computing element or elements. In someembodiments, the processor 1204 may provide part or all of theprocessing systems, processing circuitry, or processors described withreference to any of FIGS. 1, 3-5B, and 8-12 .

It should be noted that the components of the wearable device 1200 canbe controlled by multiple processors. For example, select components ofthe wearable device 1200 (e.g., the sensor system 1210) may becontrolled by a first processor and other components of the wearabledevice 1200 (e.g., the electronic display 1202) may be controlled by asecond processor, where the first and second processors may or may notbe in communication with each other.

The power source 1206 can be implemented with any device capable ofproviding energy to the wearable device 1200. For example, the powersource 1206 may include one or more batteries or rechargeable batteries.Additionally or alternatively, the power source 1206 may include a powerconnector or power cord that connects the wearable device 1200 toanother power source, such as a wall outlet.

The memory 1208 may store electronic data that can be used by thewearable device 1200. For example, the memory 1208 may store electricaldata or content such as, for example, audio and video files, documentsand applications, device settings and user preferences, timing signals,control signals, and data structures and databases. The memory 1208 mayinclude any type of memory. By way of example only, the memory 1208 mayinclude random access memory (RAM), read-only memory (ROM), flashmemory, removeable memory, other types of storage elements, orcombinations of such memory types.

The wearable device 1200 may also include one or more sensor systems1210 positioned almost anywhere on the wearable device 1200. Forexample, the sensor system 1210 may include any and all of the sensorsdiscussed herein with respect to FIGS. 1, 3-5B, and 8-12 . The sensorsystem 1210 may be configured to sense one or more types of parameters,such as but not limited to: vibration, light, touch, force, heat,movement, relative motion, biometric data (e.g., biological parameters)of a user, air quality, proximity, position, or connectedness. By way ofexample, the sensor system 1210 may include one or more interferometricsensors as discussed herein with respect to FIGS. 1, 3-5B, and 8-12 , aheat sensor, a position sensor, a light or optical sensor, anaccelerometer, a pressure transducer, a gyroscope, a magnetometer, ahealth monitoring sensor, and/or an air quality sensor. Additionally,the one or more sensor systems 1210 may utilize any suitable sensingtechnology, including, but not limited to, interferometric, magnetic,capacitive, ultrasonic, resistive, optical, acoustic, piezoelectric, orthermal technologies.

The I/O mechanism 1212 may transmit or receive data from a user oranother electronic device. The I/O mechanism 1212 may include theelectronic display 1202, a touch sensing input surface, a crown, one ormore buttons (e.g., a graphical user interface “home” button), one ormore cameras (including an under-display camera), one or moremicrophones or speakers, one or more ports such as a microphone port,and/or a keyboard. Additionally or alternatively, the I/O mechanism 1212may transmit electronic signals via a communications interface, such asa wireless, wired, and/or optical communications interface. Examples ofwireless and wired communications interfaces include, but are notlimited to, cellular and Wi-Fi communications interfaces.

The foregoing description, for purposes of explanation, uses specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art,after reading this description, that the specific details are notrequired in order to practice the described embodiments. Thus, theforegoing descriptions of the specific embodiments described herein arepresented for purposes of illustration and description. They are nottargeted to be exhaustive or to limit the embodiments to the preciseforms disclosed. It will be apparent to one of ordinary skill in theart, after reading this description, that many modifications andvariations are possible in view of the teachings herein.

As described herein, one aspect of the present technology may be thegathering and use of data available from various sources, includingbiometric data (e.g., information about a person's respiration andmovement). The present disclosure contemplates that, in some instances,this gathered data may include personal information data that uniquelyidentifies or can be used to identify, locate, or contact a specificperson. Such personal information data can include, for example,biometric data and data linked thereto (e.g., demographic data,location-based data, telephone numbers, email addresses, home addresses,data or records relating to a user's health or level of fitness (e.g.,vital signs measurements, medication information, exercise information),date of birth, or any other identifying or personal information).

The present disclosure recognizes that the use of such personalinformation data, in the present technology, can be used to the benefitof users. For example, the personal information data can be used toauthenticate a user to access their device, or gather performancemetrics for the user's interaction with an augmented or virtual world.Further, other uses for personal information data that benefit the userare also contemplated by the present disclosure. For instance, healthand fitness data may be used to provide insights into a user's generalwellness, or may be used as positive feedback to individuals usingtechnology to pursue wellness goals.

The present disclosure contemplates that the entities responsible forthe collection, analysis, disclosure, transfer, storage, or other use ofsuch personal information data will comply with well-established privacypolicies and/or privacy practices. In particular, such entities shouldimplement and consistently use privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining personal information data private andsecure. Such policies should be easily accessible by users, and shouldbe updated as the collection and/or use of data changes. Personalinformation from users should be collected for legitimate and reasonableuses of the entity and not shared or sold outside of those legitimateuses. Further, such collection/sharing should occur after receiving theinformed consent of the users. Additionally, such entities shouldconsider taking any needed steps for safeguarding and securing access tosuch personal information data and ensuring that others with access tothe personal information data adhere to their privacy policies andprocedures. Further, such entities can subject themselves to evaluationby third parties to certify their adherence to widely accepted privacypolicies and practices. In addition, policies and practices should beadapted for the particular types of personal information data beingcollected and/or accessed and adapted to applicable laws and standards,including jurisdiction-specific considerations. For instance, in the US,collection of or access to certain health data may be governed byfederal and/or state laws, such as the Health Insurance Portability andAccountability Act (HIPAA); whereas health data in other countries maybe subject to other regulations and policies and should be handledaccordingly. Hence different privacy practices should be maintained fordifferent personal data types in each country.

Despite the foregoing, the present disclosure also contemplatesembodiments in which users selectively block the use of, or access to,personal information data. That is, the present disclosure contemplatesthat hardware and/or software elements can be provided to prevent orblock access to such personal information data. For example, in the caseof advertisement delivery services, the present technology can beconfigured to allow users to select to “opt in” or “opt out” ofparticipation in the collection of personal information data duringregistration for services or anytime thereafter. In another example,users can select not to provide data to targeted content deliveryservices. In yet another example, users can select to limit the lengthof time data is maintained or entirely prohibit the development of abaseline profile for the user. In addition to providing “opt in” and“opt out” options, the present disclosure contemplates providingnotifications relating to the access or use of personal information. Forinstance, a user may be notified upon downloading an app that theirpersonal information data will be accessed and then reminded again justbefore personal information data is accessed by the app.

Moreover, it is the intent of the present disclosure that personalinformation data should be managed and handled in a way to minimizerisks of unintentional or unauthorized access or use. Risk can beminimized by limiting the collection of data and deleting data once itis no longer needed. In addition, and when applicable, including incertain health related applications, data de-identification can be usedto protect a user's privacy. De-identification may be facilitated, whenappropriate, by removing specific identifiers (e.g., date of birth),controlling the amount or specificity of data stored (e.g., collectinglocation data at a city level rather than at an address level),controlling how data is stored (e.g., aggregating data across users),and/or other methods.

Therefore, although the present disclosure broadly covers use ofpersonal information data to implement one or more various disclosedembodiments, the present disclosure also contemplates that the variousembodiments can also be implemented without the need for accessing suchpersonal information data. That is, the various embodiments of thepresent technology are not rendered inoperable due to the lack of all ora portion of such personal information data. For example, content can beselected and delivered to users by inferring preferences based onnon-personal information data or a bare minimum amount of personalinformation, such as the content being requested by the deviceassociated with a user, other nonpersonal information available to thecontent delivery services, or publicly available information.

What is claimed is:
 1. A head mounted device, comprising: a housing; oneor more interferometric sensors disposed in the housing, each of the oneor more interferometric sensors configured to: emit electromagneticradiation towards an expected airflow path for respiration of a user;and generate one or more interferometric signals including informationabout particle movement in the expected airflow path for respiration ofthe user.
 2. The head mounted device of claim 1, further comprisingprocessing circuitry communicably coupled to the one or moreinterferometric sensors and configured to determine respirationinformation about the user using the one or more interferometricsignals.
 3. The head mounted device of claim 2, wherein the respirationinformation includes one or more of: respiration rate; respirationvelocity; respiration volume; respiration quality; whether a user isbreathing through a nose or a mouth; information about particlesinhaled; or information about particles exhaled.
 4. The head mounteddevice of claim 1, wherein the one or more interferometric sensorsinclude self-mixing interferometric (SMI) sensors.
 5. The head mounteddevice of claim 1, wherein the one or more interferometric sensorsinclude Mach-Zender interferometric (MZI) sensors.
 6. The head mounteddevice of claim 2, further comprising one or more referenceinterferometric sensors, the one or more reference interferometricsensors configured to: emit electromagnetic radiation towards an areaoutside the expected airflow path for respiration of the user; andgenerate one or more reference interferometric signals includinginformation about particle movement in the area outside the expectedairflow path for respiration of the user.
 7. The head mounted device ofclaim 6, wherein the processing circuitry is communicably coupled to theone or more reference interferometric sensors and configured todetermine the respiration information about the user based on the one ormore interferometric signals and the one or more referenceinterferometric signals.
 8. The head mounted device of claim 1, wherein:the one or more interferometric sensors comprise a first interferometricsensor and a second interferometric sensor; and the firstinterferometric sensor includes one or more of a focal length, a depthof field, a numerical aperture, an angle of incidence with respect to aplane located in the expected airflow path for respiration of the user,and one or more characteristics of the electromagnetic radiation emittedtherefrom that is different from the second interferometric sensor. 9.The head mounted device of claim 2, further comprising a displaydisposed in the housing.
 10. The head mounted device of claim 9, whereinthe processing circuitry is communicably coupled to the display andconfigured to cause the display to change in response to respiration ofthe user.
 11. A method of operating a head mounted device, comprising:generating, from a set of one or more interferometric sensors disposedin a housing of the head mounted device, one or more interferometricsignals including information about particle movement caused byrespiration of a user; and determining, by processing circuitry in thehead mounted device, respiration information about the user based on theone or more interferometric signals.
 12. The method of claim 12, whereinthe respiration information about the user includes one or more of:respiration rate; respiration velocity; respiration volume; respirationquality; whether a user is breathing through a nose or a mouth;information about particles inhaled; and information about particlesexhaled.
 13. The method of claim 11, wherein the one or moreinterferometric sensors are self-mixing interferometric (SMI) sensors.14. The method of claim 11, wherein the one or more interferometricsensors are Mach-Zender interferometric (MZI) sensors.
 15. The method ofclaim 11, further comprising generating, from a set of one or morereference interferometric sensors in the housing of the head mounteddevice, one or more reference interferometric signals includinginformation about particle movement that is not caused by respiration ofthe user.
 16. The method of claim 15, wherein the respirationinformation about the user is determined based on the one or moreinterferometric signals and the one or more reference interferometricsignals.
 17. A head mounted device, comprising: a housing; one or moreinterferometric sensors disposed in the housing, each of the one or moreinterferometric sensors configured to: emit electromagnetic radiationtowards an expected airflow path for respiration of a user; and generateone or more interferometric signals including information about particlemovement in the expected airflow path for respiration of the user; and aplurality of electromagnetic radiation detectors distributed within thehousing, each of the plurality of electromagnetic radiation detectorsconfigured to generate one or more detector signals includinginformation about reflections of the electromagnetic radiation emittedfrom the one or more interferometric sensors from one or more particlesin the expected airflow path for respiration of the user.
 18. The headmounted device of claim 17, further comprising processing circuitrycommunicably coupled to the one or more interferometric sensors and theplurality of electromagnetic radiation detectors, the processingcircuitry configured to determine a particle size of one or moreparticles in the expected airflow path for respiration of the user basedon the one or more interferometric signals and the one or more detectorsignals.
 19. The head mounted device of claim 18, wherein the processingcircuitry is further configured to determine respiration informationabout the user based on the one or more interferometric signals and theone or more detector signals.
 20. The head mounted device of claim 19,wherein the respiration information includes one or more of: respirationrate; respiration velocity; respiration volume; respiration quality;whether a user is breathing through a nose or a mouth; information aboutparticles inhaled; and information about particles exhaled.